1. Field of the Invention
The present invention relates to a telescope (including a binocular telescope).
2. Description of Related Art
In a conventional telescope, it is possible to incorporate a conversion lens (rear conversion lens) on an image side of an objective lens of a master telescope whose aberration has been independently corrected to thereby achieve a telescope having a modified magnification. The requirements to incorporate such a rear conversion lens (referred to as a rear converter) are as follows: 1) no reduction of the eye relief occurs; 2) no eclipse of ambient light takes place; and, 3) there is no remarkable change in the entire length of the telescope. To try to meet these requirements, it has been proposed to make the rear converter of a single lens, for example in Japanese Unexamined Patent Publication No. 62-138815. However, this proposal cannot satisfactorily meet all the requirements.